let a:string = "18"
let b:number = 12
let c:boolean = false
let d:any = 23.456
console.log(d.toFixed(2))

let e:unknown = 34
if(typeof e === "number"){
    console.log(e.toFixed(2))
}

let f:null = null

let arr:number[]=[4,5,6]
let arr1 = [5,6,"23",true]
let arr2:string[]=["23","xsd"]

let person:object = {
    name:"xs",
    age:18
}

interface Person{
    pName:string,
    pAge:number
}
let per:Person = {
    pName:"Voldy",
    pAge:18
}
console.log(`name: ${per.pName}, age:${per.pAge}`)
let p:{name:string,age:number} = {
    name:"vo",
    age:20
}
console.log(`name: ${p.name}, age:${p.age}`)

let p1:Per = {
    name:"xiao"
}